Removing sulphur from oils



Aug. 16, 1932. A. P. sAcHs REMOVING SULPHUR FROM OILS Filed 0G17. 6, 1928 xNvENToR A1551?? PSAc//s BY A'rroRNEY Patented Aug. 16, 1932 ALBERT r. SACI-rs, or

vNIEHT. YORK, N. Y., ASSIGNOB-TO PETRQLEUM CONVERSION, COR;-

'rORArIoNOF NEW: YORK, N. Y., A c'ORPoaArrION or :mimiwleimi Rar/Lovins sULPHUR FROM OILS Application led rOctober 6, 1928. Serial No. 310,892. K

The present invention relates tothe conversion of4` hydrocarbon oils intoY compounds of lowermolecular weight andfboiling pointl 'adapted for use as motor fuel. More particularly itv relates to improvements in certain types of conversion processes. whereby oils of comparatively high sulphur content maybe converted without an. undue percentage of sulphur beingleft in the principal product of the system.

In a conversion process which involves the use; of a'4 neutral agent which is physically mingledr with the oil, it is usually desirable to haveasmuchof the sulphur 4remain with the agent as possible in order to facilitate theremovalof sulphur from the system. In the case wherein the oilnis physically mingled with a heat-carrier gas (towhich the present invention is particularly applicable) yis possible to have a considerable.v quantity of the sulphur remain Ywith the gas, Vbutvwhere the latterl 1s recycled, its sulphur content is carried back into the system causing in certain cases a great increase of sulphur in the desired product of the system, unless there is a more or less continuous removal ofthe sulphur from the gas.V y

Tn accordance Vwith. the present invention Ima-intain conditions in Jthe reaction chamber practically nonoxidizing, avoiding as much as possible amongstv other things the presence of water vapor, so that none of the sulphur or sulphur compounds will'be converted to sulphur dioxide SO2, but will largely be converted into hydrogen sulphide, HES. This hydrogen sulphide is allowed to remain in the carrier gas until such a point in the system is reached where the temperature of the gas is below the boiling point of water under the pressure obtaining in the system, wher-euponthe sulphur isy removed by the simple expedient of washing the gas with water. I havefurthermore discovered that thisstep of sulphur removal is best carried out after the cycle gas has passed through the blower used to propel the carrier gas through the system. Thus I may locate the blower immediately beyond the main condensing system, where the temperature is well below that of the boiling point of lwater whereupon carrier gas, which say,

V14.00O F., passes from the it will be found that after traversing the blower, the temperature ofthe gas will have rise-n2 several degrees, due to the partially adiabatic conditions underwhich the gas iscompressed. At'this vpoint the rewarmed gas is recooled in an aftercool'er which'may cause a further partial condensation of: liquid products. At suchV pointA llthen vpreferably wash the gas with. water, which performs the function of removing the sulphur. The recooling fand washing may be carried out together by'spraying water into the compressed gas,or they may be separate. and consecutive.

My invention will be best understood by reference to4 the followingv detailed description taken with the annexed drawing, which shows more or less diagrammatical-ly a plant to which my inventionA has been applied.`

As previouslystated, the process of oil conversion oli-.cracking to which my inventionl finds particular application consists in bringing about the conversion reaction by the use of a neutral carrier gas heated to the requisitetemperature. When the reaction has proceeded for thedesiredlength of time,

`the products from the reaction chamber are subjected to the necessary condensing conditions, including preferably various heat interchange steps for the saving of heat. This 'process in its essentials is illustrated in the drawing in which the oil, which preferably has been preheated at' another point in the system, kis shown entering the vaporizer 10 where it is vaporiz'ed under conditions which Apreferably'conduce to a minimum of crack- `ing after which through the pipe 11,

the vapors are led therefrom and thence into a reaction chamber 12. 'Also admitted to this 4chamber is a carrier gas conveniently of hyhas been passed drocarbon origin which through 'a' heating element preferably in the form of a regenerative heater 13 of the hot blast stove type which previously has been brought to the requisite temperature. The

the neighborhood of stove 13 through pipe 14 into the reaction chamber 12 wherein it mingles with theoil vapor from evaporator 10 and causes same to be converted into comin toa temperature in has been heated there- 20 by means of a pipe 24. 20

Ytering through p spray head 31.

pounds of lower molecular weight. The products from the reaction chamber 12 including the carrier gas now pass through a pipe 15 to a scrubber 16 wherein carbon is .removed'from the products without, however, condensing out of the mixture anything except the very heavy ends. F rom the scrubber 16 the products pass througha. pipe 17 to the condensing system proper which is shownV as comprised of a rectitier'18a con# duit 19, anda condenser 2O.H In vrectifier 18 the products are contacted with liquid oil at a diiferent stage in the operating cycle, as, for example, the raw Aentering'oil, the liquid products leaving the rectifierthrough a pipe 21. The lliquid products from the condensing system are collected in an ac eumulator 23 which is joined to condenser The carrier gas, together with a large proportion of the sulphur originally in the oil and also with 'someresi'dual vapors which have escaped condensation in the condensing vsystem leaves the accumulator 23 through a pipe 25 leading toa blower 26, preferably of the turbo type, serving to propel the gas Vthrough the system and in which it is necessarily compressed somewhat. From there the gas passes through a pipe 27 preferably to a cooler 27a wherein the excess heat acquired by the compression step (and such additional heat as may be desired) is removed. The vapors condensed in the cooler are removed in a trap 27h after which the gas passes through pipe 27ste a .spray condenser 28 in which the gas is sprayed bywater ena pipe 30 connecting with a Desirablv the condenser 28 contains .filling material 29 affording a large surface contact of the gas and liquid. The effect of the spray is to remove from the gas substantially all its contained sulphur, which is chiefly in the form of hydrogen sulphide.

After having passed through the scrubber 28 the gas is conveyed through a conduit 32 to-an absorber 33 wherein it is stripped of its contained vapors by the action of a suitable menstruum, as, for example, a heavy oil `which is admitted throughpipe 34. Leaving theabsorber 33 the gas, denuded of its contained vapors, passes through pipes 35,25@ back to the stove 13. If desired, all ora portion of the gas which has been additioneel V,by that produced in the conversion reaction Ymay be brought to a holder 36, for which purpose valves 37, 3,8,V 39 areprovided.

If desired,V I may omit the cooler 27 a and trap 275 altogether and remove both the heat and the sulphur in the spray condenser 28.

t will be seen from the foregoing thatk I remove the sulphur from the carrier gas Yat an advantageous point in the system at which the temperature of the gas is close to the lowest prevailing' in the system, this condition taken with the fact that the gas is also at its highest Vcarbon is broug compounds from pressure in the system (since it has just passed through the blower) making the concentration of the gaseous sulphur compounds, chiefly ILS, per unitvolume of the gas higher than at any previous point in the system, whereby at such point it is most efficiently removed. In addition, the desulphurizing step at this point in the system may perform as has l een pointed out the further function of cooling the gas which has itscompression in the blower. It will also be noted that where the water is added at a point in the system Vwhere the temperature is very vhigh as inthe conversion chamber, oxidation of a part of the sulphur to sulphur dioxide may result due to the oxidizing action of the water vapor, and whilesulphur in this form is not readily taken up by the oil condensed out in thev condensers, it has a highly corrosive effect uponthe metal parts in the system and specified and maintaining conditions in the system relatively non-oxidizing, these ditlicultie's are avoided.

TWhile I have described my invention with respect to a process of oil cracking, which I have VVdescribed in detail, it will be understood that the same is not limited to this particular process but is applicable to any process employing a gas asan aid in carrying out the cracking reaction. It will further be understood that the desulphurizing step may be carried out at points in thesystemrwhere the temperature is higher than that mentioned with corresponding loss of efficiency.

I claim:

.1. In the process of converting hydrocarbon oiis into compounds of lower molecular weight in which the conversion of the hydrot about by contacting same with a heat-*carrier gas of the requisite volume `:and heat units, the steps of cooling the gas and vapors down to below the boiling point of water under the conditions prevailing in passing the gas and residual vapors through a blower, and then spraying same with water to remove'sulphur said vapors and gas and also i to cool same to a temperature below the boiling point of water at the pressure prevailing in the system and then stripping said desul-V phurized gas of said residual vapor.

2. :In the process of converting hydrobeen heated by amountl ofV cooling water, both of from sulphur compounds and utilizing the desulphurized gas when heated as the heatcarrier to convert additional hydrocarbons.

3. In the process of converting hydrocarbon oils into compounds of lower molecular weight, in which a heat-carrier gas is used as an aid to the conversion reaction, the steps of maintaining said conversion conditions substantially non-oxidizing, passing the gas containing various of the products of the conversion reaction through a condensing system to separate the vapors of the greater portion of the converted products from the carrier gas, at which point in the system the temperature of said gas is below the boiling point of water under the pressure prevailing in the system, then spraying said gas with water to remove therefromV sulphur com-` pounds and utilizing the desulphurized gas when heated as the heat-carrier to convert additional hydrocarbons.

4. In the process of converting hydrocarbon oils into compounds of lower molecular weight suitable as motor fuels, in which a heat-carrier gas is used as an aid to the conversion reaction, the steps of passing the gas containing various of the products of the concompressing said gas whereby to `propel the same through the system and to increase the concentration of sulphur compounds therein, then removing from the gas a portion at least of the heat acquired by the compressing step,then spraying said gas with water to remove therefrom sulphur compounds when the temperature of said gas is not substantially above the boiling point of water at the pressure prevailing in the system and utilizing the desulphurized gas as the heat-carrier when heated to convert additional hydrocarbons.

In testimony whereof I have aliixed my signature to this specification. v

ALBERT P. sAcHs.

version reaction through a condensing sys- .y

prevailing in the system and utilizing the y desulphurized gas when heated as the heatcarrier to convert additional hydrocarbons.

5. In the process of converting hydrocarbon oils into compounds of lower molecular weight suitable as motor fuels, in which a heat-carrier gas is used as an aid to the conversion reaction, the steps of passing the gas containing various of the products of the conversion reaction through a condensing system to separate the vapors of the greater` portion of the converted products from the carrier gas, including said compounds of lower molecular weight suitable as motor fuels, 

